The present invention relates to the art of interactive image-guided surgery. It finds particular application in the field of brachytherapy of the prostate and will be described in particular reference thereto. It is to be appreciated, however, that the invention is also applicable to a wide range of imaging equipment and minimally invasive stereotactic and other surgical procedures including, for example, cryogenics, photo-activation concepts, other local cancer treatments, and the like.
Brachytherapy is a form of radiation therapy in which radioactive seeds are inserted into cancerous tissue, thereby attacking cancer cells. It is desirable that the seeds be distributed within the malignant tissue in a particular selected pattern. It is generally desirable that the seeds be distributed evenly so as to avoid hot (e.g., over-radiated), and cold (e.g., under-radiated) spots. Additionally, the seeds should not be placed outside of the target region.
One method for inserting the seeds in the case of prostate brachytherapy involves trans-rectal ultrasound image guidance. One disadvantage of such a procedure is that it is uncomfortable for the patient. Yet another disadvantage is that preoperative planning and visualization information is limited.
There is a need, therefore, to provide a brachytherapy planning method and apparatus that enables non-invasive preoperation planning using visualization information showing a patient""s anatomy together with one or more planning trajectories.
Preferably, the planning method and apparatus includes a localizing device for determining a position of a surgical guide device relative to the visualization information. In that way, an interventionist can move the localizing device and surgical guide device into a range of positions relative to a patient so that multiple views of a range of planning trajectories are shown on a display together with a virtual representation of the patient""s anatomy.
In accordance with the present invention, a method of non-invasive planning a brachytherapy surgically procedure on an area of a patient is provided. A volumetric image data set of an area of the patient to be treated is provided. A multi-apertured surgical planning guide device is disposed in a first position adjacent the patient to be treated. The volumetric image data set of the area of the patient is displayed on a display device with a virtual representation of the guide lattice device superimposed on the volumetric image data set to provide a visual indication of a position of the guide lattice relative to anatomy of the patient.
In accordance with a more detailed aspect of the planning method of the invention, multiple planar portions of the volumetric image data set are displayed on the display device simultaneously. A first planar portion of the volumetric image data set is coplanar with a major plane of the guide lattice device and corresponds to a physical position of the guide lattice device relative to the area of the patient. A second planar portion of the volumetric image data set is orthogonal with the major plane of the guide lattice and corresponds to a first cross-sectional view of the area of the patient with a first cross-sectional virtual representation of the guide lattice superimposed on the volumetric image data set. A third planar portion of the volumetric image data set is orthogonal with the major plane of the guide lattice and also orthogonal with the second planar portion. The third planar portion corresponds to a second cross-sectional view of the area of the patient with a second cross-sectional virtual representation of the guide lattice device superimposed on the volumetric image data set.
In accordance with a further more limited aspect of the method in accordance with the present invention, the step of providing the volumetric image data set of the area of the patient to be treated includes retrieving the data set from a data storage device such as a computer memory. In a more limited aspect, the step of providing the volumetric image data includes scanning the area of the patient using an imaging device to generate the volumetric image data set.
Still further in accordance with the invention, a first virtual needle linear planning trajectory is defined extending through the volumetric image data set from a first aperture of the multi-apertured surgical planning guide lattice device to a first virtual needle end point in the volumetric image data set. The first virtual needle linear planning trajectory is displayed on the display device. The length of the first virtual needle linear planning trajectory is selectively adjustable to extend through the volumetric image data set from the guide lattice device to a second virtual needle end point in the volumetric image data set.
Still further in accordance with the present invention, an apparatus is provided for planning a surgical procedure for inserting a plurality of objects into a patient along a plurality of surgical planning trajectories from a plurality of entry points on the patient to a plurality of target points within the patient. The apparatus includes a first device storing an image volume data set of an area of a patient to be treated. A multi-apertured surgical planning grid lattice is disposed in a first position relative to the patient for defining a plurality of linear planning trajectories extending from the planning grid lattice and through the patient. A display device is adapted for displaying the image volume data set of the area of the patient with a virtual representation of the grid lattice superimposed on the image volume data set to provide a visual image of a position of the grid lattice relative to anatomy of the patient. In that way, the grid can be physically centered over the target organ and then appropriately rotated or adjusted to align the virtual needles with the organ or to avoid critical structures in the patient.
In accordance with a more limited aspect of the planning apparatus of the present invention, the first device is preferably an imaging device adapted to scan the area of the patient to be treated to generate the image volume data set.
Still further, the apparatus for planning the surgical procedure includes a localizing means for determining a position of the grid lattice relative to the image volume data set. The display device is responsive to the localizing means for displaying the image volume data set of the area of the patient with the virtual representation of the grid lattice superimposed on the image volume data set to provide the visual representation of the position of the grid lattice relative to the anatomy of the patient.
One advantage of the present invention is that a method and apparatus are provided for planning brachytherapy surgical procedures as well as other minimally invasive surgical procedures including cryogenics, photo-activation concepts, other local cancer treatments, stereotactic procedures, and the like.
Another benefit of the invention derives from the ability of interventionists or brachytherapists to create and visualize a plurality of surgical planning trajectories into the patient relative to anatomy of the patient so that a plurality of radioactive seeds or other devices can be placed within the patient at a plurality of preselected target points.
Still other advantages and benefits of the invention will become apparent to those skilled in the art upon a reading and understanding the following detailed description.